Boards: Shock

  1. What is a normal oxygen extraction ratio in a healthy adult?
    25%

    (20 vol% - 15 vol%)/20 vol% = 5/20 = 25%
  2. What is Beck's triad for the diagnosis of cardiac tamponade?
    • 1. Hypotension
    • 2. Distended neck veins (JVD)
    • 3. Muffled heart tones
  3. What is the equation for calculating arterial oxygen content (CaO2)?
    CaO2 = (1.39 x Hgb x arterial O2 Sat) + (0.003 x PaO2)
  4. What hemodynamic changes are associated with sepsis?
    • -Decreased SVR
    • -Nml to decreased CARDIAC FILLING PRESSURES
    • -Normal or elevated MIXED VENOUS O2 SAT
    • -Increased CARDIAC INDEX
    • -Increased SVR (LATE STAGE)
  5. What are the indicators of global oxygen transport insufficiency (3)?
    • 1. Decrease in MIXED VENOUS OXYGEN SATURATION
    • 2. Increase in ARTERIAL-VENOUS OXYGEN CONTENT DIFFERENCE
    • 3. Development of LACTIC ACIDOSIS
  6. What are the clinical manifestations of the SIRS?
    • 1. Fever or hypothermia
    • 2. Tachypnea
    • 3. Tachycardia
    • 4. Increased WBC w/ left shift
  7. What are the mechanisms of obstructive shock (2)?
    • 1. IMPEDANCE TO FILLING
    • -tamponade
    • -restrictive cardiomyopathies

    • 2. IMPEDANCE TO OUTFLOW
    • -PE
    • -valvular stenosis
  8. What is the classic hemodynamic finding of cardiac tamponade?
    EQUALIZATION OF DIASTOLIC PRESSURES of the heart chambers
  9. Why does removal of very little pericardial fluid in tamponade greatly improve the clinical picture?
    Tamponade occurs at the right side of the pericardial compliance curve where small decreases in volume cause large decreases in pressure
  10. What causes electrical alternans on the ECG of a pt with cardiac tamponade?
    Cyclic motion of the heart in a fluid-filled pericardial sac
  11. What is pulsus paradoxus?
    A greater than normal DECREASE in systolic arterial pressure with INSPIRATION
Author
Reed.Simons
ID
95641
Card Set
Boards: Shock
Description
Boards: Shock
Updated